Neuroscience, Mindreading, and the Courts: the Example of Pain Henry T

Journal of Health Care Law and Policy Volume 18 Issue 2 Imaging the Brain, Changing Minds: Chronic Article 2 Pain Neuroimaging and the Law Neuroscience, Mindreading, and the Courts: The Example of Pain Henry T. Greely Follow this and additional works at: http://digitalcommons.law.umaryland.edu/jhclp Part of the Health Law Commons, and the Neurosciences Commons Recommended Citation Henry T. Greely, Neuroscience, Mindreading, and the Courts: The Example of Pain, 18 J. Health Care L. & Pol'y 171 (2015). Available at: http://digitalcommons.law.umaryland.edu/jhclp/vol18/iss2/2 This Symposium is brought to you for free and open access by the Academic Journals at DigitalCommons@UM Carey Law. It has been accepted for inclusion in Journal of Health Care Law and Policy by an authorized administrator of DigitalCommons@UM Carey Law. For more information, please contact [email protected]. NEUROSCIENCE, MINDREADING, AND THE COURTS: THE EXAMPLE OF PAIN HENRY T. GREELY* Our brains hold about 100 billion neurons.1 At the synapses where neurons connect, the neurons are constantly giving off and picking up chemicals called neurotransmitters, which in turn can cause those neurons to “fire”—to run cascading ions down the neurons’ “wires” or axons.2 And that process creates the Universe we live in.3 Not quite, literally. I do believe, though I cannot rigorously prove, that you exist, the Earth exists, and the Universe exists outside of our own brains, but our only interaction with that reality is through our brains and the physical events that happen there. Those objective physical events create a subjective and non-physical “thing” we call the mind. If you remember tomorrow that you read this Article (or this much of the Article), it is because this Article (and I) will have made physical changes to your brain. As we get better at looking at those physical changes in the brain through various new technologies, we can begin to correlate those objective physical brain states with subjective mental states.4 We can begin to say Copyright © 2015 by Henry Greely. * Henry Greely is the Deane F. and Kate Edelman Johnson Professor of Law and Professor, by courtesy, of Genetics at Stanford University, where he directs the Center for Law and the Biosciences, and the Stanford Program in Neuroscience and Society. This Article is adapted from the author's Stuart Rome Lecture, delivered at the University of Maryland Carey School of Law on April 24, 2014. 1. Suzana Herculano-Houzel, The Human Brain in Numbers: A Linearly Scaled-Up Primate Brain, FRONTIERS HUMAN NEUROSCIENCE (Nov. 9, 2009), http://journal.frontiersin.org/article/10.3389/neuro.09.031.2009/full. 2. See HARVEY LODISH ET AL., MOLECULAR CELL BIOLOGY 935 (4th ed. 2000) (explaining the process by which a neurotransmitter, which originates at the presynaptic neuron, sends a signal when it is sent to the postsynaptic target cell). 3. See Robert Lanza, A New Theory of the Universe: Biocentrism Builds on Quantum Physics by Putting Life Into the Equation, AM. SCHOLAR (Mar. 1, 2007), https://theamericanscholar.org/a-new-theory-of-the-universe/#.VRIZjjTF-Hw. 4. See B. ALAN WALLACE, MIND IN THE BALANCE: MEDITATION IN SCIENCE, BUDDHISM, AND CHRISTIANITY 23 (2009) (noting the difference between objectively studying the brain and understanding the subjective mental state that is occurring simultaneously). 171 Greely Final.docx 172 JOURNAL OF HEALTH CARE LAW & POLICY [VOL. 18:171 “any time you move the big toe on your left foot, these neurons fire,” or “every time you see a face, those neurons fire.”5 Consider, for example, some spectacular work by Professor Jack Gallant at the University of California at Berkeley.6 Gallant’s group showed thousands of hours of YouTube videos to some volunteers while they were in a magnetic resonance imaging (“MRI”) scanner.7 The MRI noted the changes at different times in the relative amounts of oxygenated and de- oxygenated hemoglobin in different parts of the volunteers’ brains, in a process called functional magnetic resonance imaging (“fMRI”).8 Computers analyzed the resulting data and found correlations between what the volunteers were seeing at any given time and the patterns of these hemodynamic changes.9 Gallant then took different volunteers, put them in the MRI scanner, and showed them trailers from movies.10 His team took the resulting brain scans and, using the correlations from the original work, “re-created” the scenes from the trailers as the volunteers saw them.11 The results are far from perfect—but still close to amazing. When, in a trailer, an elephant walks across a plain from left to right, the recreation of what the viewer sees from the viewer’s brain scan shows something that looks like an elephant-shaped haystack walking from left to right across a plain.12 The results come from correlating perceived physical states of the brain with 5. See Ferris Jabr, Know Your Neurons: How to Classify Different Types of Neurons in the Brain’s Forest, SCI. AM. (May 16, 2012), http://blogs.scientificamerican.com/brainwaves/2012/05/16/know-your-neurons-classifying-the- many-types-of-cells-in-the-neuron-forest/ (noting that neurons are classified by function because neurons that carry sensory information are not the same neurons that carry signals for motor function in the body). 6. See Yasmin Anwar, Scientists Use Brain Imaging to Reveal the Movies in Our Mind, UC BERKELEY NEWS CENTER (Sept. 22, 2011), http://newscenter.berkeley.edu/2011/09/22/brain- movies (citing the cutting-edge work by Prof. Jack Gallant and his lab, which have successfully reconstructed humans’ visual experiences through computer simulation as the participants watched Hollywood movie trailers); see also Shinji Nishimoto et al., Reconstructing Visual Experiences from Brain Activity Evoked by Natural Movies, GALLANT LAB @ UC BERKELEY http://gallantlab.org/publications/nishimoto-et-al-2011.html (last updated June 18, 2014) (explaining the use of an fMRI machine to measure brain activity during the experiment, and the computational models used to reconstruct what participants saw). 7. Anwar, supra note 6. 8. Id. 9. Id. 10. Id. 11. Id. 12. See Malcolm Ritter, Mind-Reading Technology Reconstructs Videos from Brain, SYDNEY MORNING HERALD (Sept. 23, 2011), http://www.smh.com.au/technology/sci-tech/mindreading- technology-reconstructs-videos-from-brain-20110923-1ko5s.html (noting that human forms were more recognizable in reconstructions, while figures such as elephants did not transition so clearly). 2015] NEUROSCIENCE, MINDREADING, AND THE COURTS 173 subjective mental states.13 It comes from, in some small way, reading minds. This Article is about mindreading and its applications to the law. We are beginning to be able to use neuroimaging and other techniques to read minds.14 Most of the attention in the burgeoning field of law and neuroscience has focused on issues of free will and criminal responsibility, but the most important contribution that neuroscience will make to the law will be through neuroscience-based mindreading. And I suspect its first important use will be in the area of detecting “pain,” on which this Article will focus.15 This Article makes that argument in four parts. First, it looks at what kind of evidence the law currently uses to read minds, and how neuroscience-based evidence would and would not be different.16 Second, it discusses some of the possible ways the law could use neuroscience-based mindreading.17 Third, in its most novel contribution, it analyzes what kind of proof the law should demand of the accuracy of such mindreading techniques—and what we would have to invest in developing these technologies to be confident in their use.18 Finally, it touches on one of the deepest problems that might be raised by the use of accurate mindreading evidence in the law.19 13. Anwar, supra note 6. 14. See Rob Hoskin, Can a Neuroscientist Read Your Mind?, SCIENCE BRAINWAVES (Apr. 30, 2012), http://www.sciencebrainwaves.com/uncategorized/can-a-neuroscientist-read-your- mind/ (highlighting the neural information that occurs even before a decision is made). 15. The implications for the legal system of neuroimaging of evidence of pain is the subject of a small, but growing literature. See Adam J. Kolber, The Experiential Future of the Law, 60 EMORY L.J. 585, 651 (2011) (identifying the need for more objective units to describe certain experiences, like pain); Adam J. Kolber, Pain Detection and the Privacy of Subjective Experience 33 AM. J.L. & MED. 433, 453–54 (2007) (noting the need for more privacy for records regarding pain); Amanda C. Pustilnik, Imaging Brains, Changing Minds: How Neuroimaging Can Transform the Law’s Approach to Pain, 66 ALA. L. REV. (forthcoming 2015); Amanda C. Pustilnik, Pain as Fact and Heuristic: How Pain Neuroimaging Illuminates Moral Dimensions of Law, 97 CORNELL L. REV. 801, 805 (2012) (highlighting that it is a major challenge to assign values to brain imaging, just as it is a challenge to do the same for pain when attempting to create law). 16. See infra Part I. 17. See infra Part II. 18. See infra Part III. 19. See infra Part IV. I have discussed some of these issues about mindreading twice before in some depth. See Henry T. Greely, Neuroscience, Mindreading and the Law, in A PRIMER ON CRIMINAL LAW AND NEUROSCIENCE 120–49 (Stephen J. Morse & Adina L. Roskies eds., 2013); Emily R. Murphy & Henry T. Greely, What Will Be the Limits of Neuroscience-Based Mindreading in the Law?, in THE OXFORD HANDBOOK OF NEUROETHICS (Judy Illes & Barbara Sahakian eds., 2011) (identifying the technical barriers to meaningful mindreading, including the likely impossibility of creating a complete model of the human brain).

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